The sea is OK for swimming, though there are often high waves that may be good for surfing, too.
No good snorkelling around as the shore is pretty sandy.
There are two nice, long, sandy beaches: Hat Sai Kaew and Hat Khiriwong.
They are both unspoilt and deserted.
The only drawback is that there are no facilities at all and you may have to walk for kms before finding drink or food.
There is a dirt track running parallel to the beach ahere there are occasional farmers truck that may give you a lift.
It is difficult to reach this remote coastal area.
Only a few local trains stop at the tiny Ban Khok Ta Hom railway station: take care not to miss it as it is just a small hut along the rails without any board!
The train stop is a couple of kms from the beaches and the resorts; you can easily find a lift from the local guys waiting for people arriving by train.